Accessing Current Location with GPS in Android Apps

Introduction

In this tutorial, we’ll explore how to access a user’s current location using GPS on an Android device. We will cover two primary methods: using the traditional LocationManager and leveraging the Google Play Services API for more efficient and modern implementations.

Prerequisites

• Basic understanding of Java programming.
• Familiarity with Android development (Android Studio, XML layouts).
• An Android device running Android 6.0 (Marshmallow) or above is recommended due to permission requirements.

Accessing Location Using LocationManager

The LocationManager class allows you to access the location services on a device. Here’s how to use it to get GPS coordinates:

Step 1: Add Permissions

First, ensure that your app has the necessary permissions by adding them to your AndroidManifest.xml file:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

For devices running Android 6.0 or higher, you’ll also need to request location permissions at runtime.

Step 2: Set Up LocationManager

In your activity, initialize the LocationManager and check if GPS is enabled:

import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    private LocationManager locationManager;
    private MyLocationListener locationListener;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        // Check if GPS is enabled and request updates.
        if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
            locationListener = new MyLocationListener();
            locationManager.requestLocationUpdates(
                LocationManager.GPS_PROVIDER, 
                5000, // Minimum time interval between notifications
                10,   // Minimum distance change to trigger an update
                locationListener);
        }
    }

    private class MyLocationListener implements LocationListener {
        @Override
        public void onLocationChanged(Location loc) {
            String message = "Latitude: " + loc.getLatitude() +
                             ", Longitude: " + loc.getLongitude();
            Toast.makeText(MainActivity.this, message, Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onProviderDisabled(String provider) {}

        @Override
        public void onProviderEnabled(String provider) {}

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {}
    }
}

Step 3: Handle Runtime Permissions

For Android 6.0 and above, you must request location permissions at runtime:

if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
        != PackageManager.PERMISSION_GRANTED) {
    ActivityCompat.requestPermissions(this,
            new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
}

Handle the permission response in onRequestPermissionsResult.

Step 4: Optimize Battery Usage

Be mindful of battery usage. Request location updates only when necessary and choose appropriate time/distance intervals.

Using Google Play Services for Location Updates

Google Play Services provides an advanced and efficient way to handle location data through its FusedLocationProviderClient.

Step 1: Add Google Play Services Dependency

Include the dependency in your build.gradle file:

implementation 'com.google.android.gms:play-services-location:21.0.1'

Step 2: Set Up GoogleApiClient and LocationRequest

In your activity, initialize GoogleApiClient, LocationRequest, and other necessary components.

import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;

public class MainActivity extends AppCompatActivity {

    private FusedLocationProviderClient fusedLocationClient;
    private LocationCallback locationCallback;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);

        createLocationRequest();
    }

    private void createLocationRequest() {
        LocationRequest locationRequest = LocationRequest.create()
                .setInterval(10000) // 10 seconds
                .setFastestInterval(5000) // 5 seconds
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        
        locationCallback = new LocationCallback() {
            @Override
            public void onLocationResult(LocationResult locationResult) {
                if (locationResult == null) return;
                for (Location location : locationResult.getLocations()) {
                    // Update UI with location data
                }
            }
        };
    }

    private void startLocationUpdates() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(
                this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
            return;
        }

        fusedLocationClient.requestLocationUpdates(createLocationRequest(),
                locationCallback, Looper.getMainLooper());
    }
}

Step 3: Request Permissions and Start Updates

Ensure you handle runtime permissions similarly as with LocationManager, then start location updates using the startLocationUpdates() method.

Conclusion

Both methods provide a way to access current GPS locations in Android applications. While LocationManager is straightforward, Google Play Services offers more efficient handling of location data and battery management through its FusedLocationProviderClient API. Choose the one that best fits your project’s needs and consider user privacy and consent when accessing location data.